The present invention relates to a method, apparatus and product relating to fibrous mat and more particularly to a unique and novel arrangement for making fibrous mat in such a combined manner that the resulting attenuated fibrous layered mat has fiber layers, each of select fiber size distribution and, if elected, a controlled surface and variable permeability.
The present invention has particular applicability to polymer fibrous mat produced by melt blowing die apparatus but it is to be understood that the present invention can be readily utilized in layered mat production wherein layered fibrous mats of other fibrous materials in addition to preselected polymer materialxe2x80x94such as glassxe2x80x94are extracted in die attenuated form from heated die sources unto spaced collector sources.
Layered fibrous mat composed of fibers attenuated from a heated die source unto a spaced layered mat collector surface are generally well known in both the glass and melt blown arts but none have utilized the unique and novel unified arrangement disclosed herein. Although, as above-noted, the present invention is not to be considered as limited to die feeding polymer materials from heated melt blown die sources, the unique and novel arrangement set forth herein has particular applicability in the melt blowing die feeding arrangements as disclosed in the U.S. Pat. Nos. 5,725,812, issued to Kyung-Ju Choi on Mar. 10, 1998; 5,891,482, issued to Kyung-Ju Choi on Apr. 6, 1999; 5,976,209, issued to Kyung-Ju Choi on Nov. 2, 1999; 5,976,427, issued to Kyung-Ju Choi, also on Nov. 2, 1999; 6,159,318, issued to Kyung-Ju Choi on Dec. 12, 2000; and 6,230,776, issued to Kyung-Ju Choi on May 15, 2001.
The external treatment of fibers with respect to a fiber collecting source is generally well known in the production of non-woven fabrics, attention being directed to U.S. Pat. No. 4,095,312, issued to D. J. Haley on Jun. 20, 1978, wherein fibers are collected from two fiber feeding sources to a pair of moving collecting surfaces to form a nip; to U.S. Pat. No. 4,100,324, issued to R. A. Anderson, et al. on Jul. 11, 1978, wherein wood pulp fibers are added to a matrix of collected polymeric melt blown micro fibers; to U.S. Pat. No. 4,267,002, issued to C. H. Sloan on May 21, 1981, wherein fibers are formed in elongated rod shape with a heavy build-up in a central portion and a light build-up in a lip portion folded back over the central portion; to U.S. Pat. No. 4,375,446, issued to S. Fujii, et al. on Mar. 1, 1983, wherein melt blown fibers are collected in a valley-like fiber-collecting zone formed by relatively moveable and compressible porous plates which have a controlled number of pores; and, finally to U.S. Pat. No. 4,526,733, issued to J. C. Lau on Jul. 2, 1955, wherein a fluid stream of attenuated fibers is preselectively temperature treated upon exiting die tip orifices to provide improved collected web properties.
Although these above-noted patents disclose various external treatments of fiber streams attenuated from heated die sources, none teaches or suggests, either alone or in combination, the economical and straight-forward arrangement which includes successively feeding and combining fiber layers, each layer having select fiber size distributions and, if elected, the novel diversion and vortically creating force exertion of a selected portion of fiber streams to provide fiber layers with select fiber size distributions, selected surface, and, selected variable permeability of the total fibrous mat as it passes to a fiber collecting source.
The present invention provides a unique and novel die attenuated fiber arrangement including a straight-forward, economical and inventively unified production method, apparatus and final layered, relatively strong fibrous mat product which allows for efficient and economic control of fiber size distribution, surface, and permeability of a layered fibrous mat product which can have selected fiber size distributions, variable density, permeability and surface.
The present invention accomplishes the unique features thereof with a minimum of apparatus, parts, elements, and method steps in both manufacture and maintenance and, at the same time, which allows for ready adjustment to control variable fiber mat density, fiber distribution, mat permeability and surface in selected areas of a produced fibrous mat.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.
More particularly the present invention provides a unified, unique and novel method, apparatus and product arrangement in the production of die attenuated fibrous mat which can be utilized in any number of commercial environmentsxe2x80x94one of which being the fluid filtration art.
Specifically, the present invention provides a unique and novel method of forming a web of fibrous media comprising: feeding fibers in attenuated multiple fiber layers from a first spaced orifice zone in a first feed path to a first selectively spaced, longitudinally extending, rotating collector zone in successive lower and upper fiber layers, the first fibers having a first selected fiber size distribution when passed to the first collector zone to form a first fibrous mat having a first selected fiber size distribution; feeding the first formed fibrous mat to at least a second similarly rotating collector zone selectively spaced from the first rotating collector zone; feeding second fibers in attenuated multiple fiber layers from a second spaced orifice zone in a second feed path to a second similarly rotating collector zone selectively spaced from the second orifice zone to form a second fibrous mat combined with the first fibrous mat fed to the second collector zone from the first collector zone, the second fibers having a second selected fiber size distribution and, feeding the combined fiber mat from the second collector source zone to a third mat forming zone.
In addition, the present invention provides several embodiments of method steps for controlling the outer surface or surfaces of the web of filter media formed by the novel method embodiments described herein.
Further, the present invention provides in a unified manner, a unique and novel mat of fibrous media comprising: at least a first layered mat portion of selected first fiber size distribution and permeability and at least a second layered mat portion of selected second fiber size distribution, and permeability, both the first and second layered mat portions being of substantially aligned fibers of first and second selected fiber size distributions, and permeabilities with each being attenuated as layers from spaced die sources directly to separate spaced similarly rotating collector sources with one of such sources receiving the layered mat portion from the other of the spaced collector sources.
In addition, the present invention provides apparatus for manufacturing a fibrous mat comprising a first die source including spaced die orifices capable of feeding a first attenuated multiple fiber layered portion; a first selectively gap spaced longitudinally extending first rotating collector surface to eventually receive the totality of the first layered portion; at least a spaced second die source including spaced die orifices capable of feeding a second attenuating multiple fiber layered portion; a second selectively gap spaced longitudinally extending second similarly rotating collector surface to eventually receive the totality of the second fiber layered portion, the second rotating collector surface being spaced from the first rotating collector surface; and, transfer and orientation means positioned between the first and second collector surfaces to orient and transfer the first layered mat portion from the first rotating collector surface to a select quadrant of the second similarly rotating collector surface.
Moreover, the present invention provides several novel rotating collector surface embodiments associated with the unique apparatus described herein to control the nature, permeability and strength of the outer surfaces and the fiber composition therebetween of the novel fibrous media mat described herein.
It is to be understood that various changes can be made by one skilled in the art in the several steps of the method and the several elements and parts of the product and apparatus herein disclosed without departing from the scope or spirit of the present unified invention.